Merge pull request #3765 from knil-sama/knil-sama-patch-rebuild-envir…

…onment

Update layer1.py

boto/beanstalk/layer1.py

@@ -773,6 +773,7 @@ def rebuild_environment(self, environment_id=None, environment_name=None):
            both.  If you do not specify either, AWS Elastic Beanstalk returns
            MissingRequiredParameter error.

        :raises InvalidParameterValue: If environment_name doesn't refer to a currently active environment
        :raises: InsufficientPrivilegesException
        """
        params = {}